This experiment was designed to test various learning theories in the conte
xt of a Courmot oligopoly. We derive theoretical predictions for the learni
ng theories and test these predictions by varying the information given to
subjects. The results show that some subjects imitate successful behaviour
if they have the necessary information, and if they imitate, markets are mo
re competitive. Other subjects follow a best reply process. On the aggregat
e level we find that more information about demand and cost conditions yiel
ds less competitive behaviour, while more information about the quantities
and profits of other firms yields more competitive behaviour.